Level-glass.



No. 674,|07. Patented Mav I4. 190i. J. A. TRAUT.

LEVEL GLASS. (Application filed Apr. 4, 1900.) (No Model.)

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UNITED STATES PATENT OFFICE.

JUSTUS A. TRLAUT, OF NEW BRITAIN, CONNECTICUT.

LEVEL-G LASS.

SPECIFICATION forming part of Letters Patent NO. 674,107, dated May 14, 1901.

Application filed April 4, 1900.

T0 at whom it may concern:

Be it known that I, J USTUS A. TRAUT, a citizen ofthe United States, residingin New Britaim, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Level- Glasses, of which the following is a specification.

This invention relates to what are known as level-glasses, which consist of tubes of transparent material nearly filled with fluid, usually alcohol, the remaining space in the tube containing a bubble of air, which occupies a position in the tube known as the reading-surface when the latter is horizontal. Heretofore' it has been impossible at times clearly to distinguish the bubble; and the primary object of my invention is the provision of means for overcoming this defect by causing the bubble to assume a distinctive appearance different from its usual character and to thereby be brought more clearly and sharply within the line of vision, so that its position in the tube may be read without I have discovered that the walls of the liquid displaced by the bubble act as reflecting-surfaces and that they will reproduce to the eye an appearance of color or other distinguishing contrast surface or media by which the bubble will be made more readily visible. To accomplish this result, any of the colors of the solar spectrum may be used with good effects, and the color selected will be reflected by the liquid displaced by the air-bubble, thereby causing said bubble to assume, particularly at its ends, the appearance of the color. Furthermore, both the glass of which the level is composed and the liquid contained in said glass act as lenses having more or less magnifying power, and consequently the distinguishing characteristic of the bubble is enlarged in this manner.

In one way of producing the result set forth certain portions of the tube of the level-glass, either one or both ends thereof, may be coated with, have applied to, or'be embedded in a contrast-surface of any desired kind, preferably a color, the reflection of which will appear upon the bubble.

Usually the level-glass is mounted in a carrier in such a way that the contrast surface or surfaces will be concealed from view; but

Serial No. 11,485. (No model.)

it is immaterial to the invention in what manner this is carried out, for whether concealed or in plain view said surface will be reflected upon the bubble in the manner set forth.

Referring to the accompanying drawings, in which like numerals designate similar parts throughout the several views, Figure '1 is a plan view, on an enlarged scale, of a levelglass and its holder, illustrating the principle of my invention. Fig. 2 is alongitudiual section, partiallyin elevation, of the holder, showing the level-glass in side elevation; and Fig. 3 is a side view of a level-glass, greatly enlarged, illustrating a contrast-surface consisting of coloring material applied to one end of the level-glass and also illustrating by heavy black lines the representation of said contrast-surface upon the bubble.

Referring to the drawings, the numeral 5 designates a level-glass of common construction, 6 an air-bubble within said glass, and 7 7 the marks or indented surfaces which divide off whatis known as the reading-space of the glass from the remainder thereof, and these indicating-marks may be formed in any desired way, but will preferably be produced in the manner set forth in the patent dated June 23, 1896, No. 562,679, granted to myself and J. A. Bodmer.

Located at any suitable point on or adjacent o end of the level-glassisa contrast-surface or distinguishing media, (designated by the numeral 8,) and for convenience of illustration this contrast-surface is shown applied to one end of the level-glass, although it may be applied to the other end thereof, if necessary, as shown at 8, Figs. 1 and 2.

It will be observed by reference to Figs. .1 and 2 of the drawings that the contrast-surface isnot in the direct line of vision of the reading-space of the level-glass, and consequently said distinguishing media or contrast-surface is reflected upon the bubble and appears thereon in substantially the manner indicated by the heavy lines 12 12 in said figures.

Usually the level-glass is mounted in a carrieror holder 9 and is embedded in some suitable material 10, such as cement or plasterof-paris, as illustrated in Figs. 1 and 2. It is immaterial, however, in what way the levelglass is mounted or whether it be employed alone or in connection with a carrier or holder, as shown.

It will be seen by reference to the figures of the drawings that the air-bubble (3 displaces a certain amount of the liquid contained in the glass, thereby producing a crescent-shaped depression therein, the surfaces of which act as mirrors or reflectors to represent upon the bubble or upon the layer of liquid adjacent thereto the contrast-surface or distinguishing media employed. This crescent-shaped surface of the liquid displaced by the bubble also acts in the nature of a meniscus-lens having one concave and one convex surface, and in looking downward upon the level-glass the line of vision is deflected, as shown by the dotted lines in Fig. 3, and the appearance of the contrast-surface is reflected upon the bubble or the liquid adjacent thereto, as shown by the heavy lines 12 12, Fig. 3. This contrast-surface or distinguishing media,therepresentation of which appears upon the bubble, may be of any kind suitable for the purpose; but I have found in practice that a simple way of producing the effect described is to coat the ends of the level-glass with a suitable pigment or color, the reflection of which clearly appears upon the bubble in the manner before stated.

Connected with the holder 9, which is cut away in the center at each side at 9', adjacent to the reading-surface of the level-glass, are the usual projections 9 and 9 by which the holder may be secured in position in any desired way.

I am aware that for many years it has been proposed to intensify the appearance of the bubble by means of either plain or colored mirrors employed for reflective purposes. These mirrors, however, add to the cost of the device and, moreover, fail to bring out the color or other con trast-surface solely upon the bubble, where it is most needed, and consequently have seldom been employed. In my improvement the mirrors are dispensed with, and the effect upon the bubble is accomplished under the laws of optics in a different way and without diffusion of the reflected surface from the point or points where it is most beneficial.

Without limiting my invention to any particular contrast-su rface for accomplishing the result set forth, what I claim is- 1. A level-glass combined with a contrastsurface located at and applied to the end of said glass outside the reading surface thereon, whereby the reflection of said coutrast-surface appears upon the bubble of the glass.

2. A level-glass containing a liquid and an air-bubble, and having a coating constituting a contrast-surface applied to one of its ends outside the readin -surface thereon.

3. The combination, with a carrier, of a level-glass embedded in said carrier and having each of its ends coated with a color outside the reading-surface thereon, the reflections of which appear upon the ends of the bubble of said glass.

J USTUS A. TRAUT.

Witnesses:

SADIE L. FINNIG-AN, STANLEY PARKER. 

